Video: Impact Caused Tesla Battery Fire

A fire in a Tesla Model S electric sedan has once again placed a spotlight on the issue of lithium-ion battery safety.

The incident, captured on a now-viral video, occurred after the vehicle rolled down an off-ramp in a suburban area between Seattle and Tacoma, Wash. Soon after it stopped and the driver exited, the car's front end was engulfed in flames.

Tesla told Design News (a sister publication) in an email:

The fire was caused by the direct impact of a large metallic object to one of the 16 modules within the Model S battery pack. Because each module of the battery pack is, by design, isolated by fire barriers to limit any potential damage, the fire in the battery pack was contained to a small section in the front of the vehicle.

A CT scan image of a battery cell shows the breakdown of layers directly below an indentation. A recent report from Underwriters Laboratories Inc. said that such dents in the casing are a possible failure mechanism for lithium-ion batteries. "The resulting high stress/strain will lead to a mechanical failure of the separator (with failure of the casing), allowing for direct contact between electrodes at a distance onlya few layers below the casing surface.”(Source: Underwriters Laboratories Inc.)

Teslas are less than a year old and they've made less than 20,000 of these cars in all (wikipedia). Unless somebody can show me gasoline engine cars catch fire at a higher than 1/20,000 rate in their first year of service, this is a serious issue deserving serious attention.

the combustion potential of that bettery is a fraction of what you would find in a typical gasoline fueled vehicle. Sure, there's a possibility of it catching fire, and that is life threatening, but there's the same risk with your typical gas powere vehicle.

The video of the Tesla Model S fire accident is pretty scary. Though it is being justified as being caused by the battery getting damaged by hitting into something and this could be a rare incident, but it is dangerous and could be life threatening. I am sure a detailed investigation would reveal the real reason and something will be done to prevent it, but I guess more research is need in knowing all possible failure modes of of Li-ion battery. Also I learned that the fire from Li-ion batteries is not controlled easily...another area for more research, which I guess is already going on.